Charge Asymmetry in the Decay<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msubsup></mml:mrow><mml:mo>→</mml:mo><mml:mi>π</mml:mi><mml:mi>μ</mml:mi><mml:mi>ν</mml:mi></mml:math>

If ${\ensuremath{\Gamma}}_{\ifmmode\pm\else\textpm\fi{}}=\mathrm{Rate}({K}_{L}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{\mp}}{\ensuremath{\mu}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\nu})$, the ${K}_{\ensuremath{\mu}3}^{0}$ charge asymmetry is $\ensuremath{\delta}=\frac{({\ensuremath{\Gamma}}_{+}\ensuremath{-}{\ensuremath{\Gamma}}_{\ensuremath{-}})}{({\ensuremath{\Gamma}}_{+}+{\ensuremath{\Gamma}}_{\ensuremath{-}})}$. This number has been measured to be (6.0\ifmmode\pm\else\textpm\fi{}1.4) \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}3}$ at the Lawrence Berkeley Laboratory's Bevatron. The error is meant to be interpreted as one standard deviation and contains a major systematic contribution. Large corrections were made in order to exclude neutron-induced background events and to correct for the range difference between ${\ensuremath{\mu}}^{+}$ and ${\ensuremath{\mu}}^{\ensuremath{-}}$. The meaning of the possible difference between muonic and electronic charge asymmetries is discussed.